Note: try to involve every premise (the given lines) to find the conclusion. 1. p -> (q & r) 2. ~t -> (~r v ~s) Therefore: (p & s) -> t ---------------------------------------------- 3. ~~t v (~r v ~s) 2 Material Implication 4. t v (~r v ~s) 3 Double Negation 5. (~r v ~s) v t 4 Commutation 6. ~r v (~s v t) 5 Association 7. ~r v (s -> t) 6 Material Implication 8. r -> (s -> t) 7 Material Implication 9. ~p v (q & r) 1 Material Implication 10. (~p v q) & (~p v r) 9 Distribution 11. (~p v r) & (~p v q) 10 Commutation 12. ~p v r 11 Simplification 13. p -> r 12 Material Implication 14. p -> (s -> t) 13,8 Hypothetical Syllogism 15. (p & s) -> t 14 Exportation